Kentaro Doi^1,2, Yuzuru Chikasako¹, Satoyuki Kawano^1,3

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.1, pp. 1-26, 2015, DOI:10.3970/fdmp.2015.011.001

Abstract Propylene carbonate (PC) and ethylene carbonate are known as good candidates of organic solvents to be used in Li-ion rechargeable batteries, since Li⁺ ions exhibit preferable charge-discharge characteristics with such solvents. On the other hand, polar solvents usually form solvation shells with solute ions, and cause a drastic reduction of ionic conductivity. Along these lines, there has been a curious question why the diffusion coefficient D_Li of Li⁺ strongly depends on the salt concentration. In the present study, a theoretical model is developed on the basis of the Langevin equation in which the interactions between ions and solvent molecules are… More >

S. Srinivasan¹, M. Z. Saghir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.2, pp. 201-216, 2011, DOI:10.3970/fdmp.2011.007.201

Abstract CFD simulations have been made to understand the impact of the vibrations of the ISS on the thermodiffusion process. Simulations were made for two ternary hydrocarbon mixtures and one binary associated mixture. While one of the ternary mixture was at a pressure of 35 MPa, the second ternary mixture as well as the binary mixture were at a pressure of 0.101325 MPa. The analysis of the results showed that imposing the ISS vibrations had a profound effect on the Soret effect in all three systems. More precisely, in all three mixtures, a single convective flow cell is established. Such a… More >

A. B. Mahmud Hasan^1,2, S.M. Guo¹, M.A. Wahab¹

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.4, pp. 399-410, 2009, DOI:10.3970/fdmp.2009.005.399

Abstract The effects of gas flow channel design were studied experimentally for increasing fuel cell performance and fuel optimization. Three types of gas flow channels (serpentine, straight and interdigitated) were designed on the basis of water flooding due to electrochemical reactions, electro-osmotic drag, etc. Experimental results indicate that the best cell performance can be obtained by arranging interdigitated gas flow channel at the anode side and serpentine gas flow channel at the cathode side. Detailed analysis on complex two phase water generation and electrochemical phenomena behind those results were analyzed in this work to find out the best design for gas… More >

N. Armour¹, S. Dost^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.4, pp. 331-344, 2009, DOI:10.3970/fdmp.2009.005.331

Abstract A combined numerical and experimental investigation has been undertaken to explore the benefits of an applied static magnetic field on Silicon transport into a Germanium melt. This work utilized a similar material configuration to that used in the Liquid Phase Diffusion (LPD) and Melt-Replenishment Czochralski (Cz) growth systems. The measured concentration profiles from the samples processed with and without the application of magnetic field showed very similar shape. The amount of silicon transport into the melt is slightly higher in the samples processed under magnetic field, and there is a substantial difference in dissolution interface shape indicating a change in… More >

R. Abdeljabar¹

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.2, pp. 193-210, 2009, DOI:10.3970/fdmp.2009.005.193

Abstract A theoretical model has been developed to predict the expansion of a salty gradient (i.e. the interface) layer under natural diffusion. The salty gradient layer is initially sandwiched between two homogeneous miscible layers of varying salinity, which may or may not have the same thickness. The model describes the concentration profile of the salty gradient layer (expressed by analytical solutions of the diffusion equation) as the boundaries of this interfacial layer move into the adjacent (hitherto homogeneous) regions. The lifetime of the adjacent layers is also predicted. An experimental study for a configuration with salty water below and distilled water… More >

L. Bennamoun¹, A. Belhamri², A. Ali Mohamed

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.2, pp. 177-192, 2009, DOI:10.3970/fdmp.2009.005.177

Abstract This study focuses on the interplay between drying kinetics (encountered in typical industrial processes and particularly in the context of solar drying) and the possible variation of external (e.g., environmental) conditions. Theoretical models of these behaviours are introduced. Experimental results confirmed by simulation are also presented. Variation of the thermo physical properties of air is taken into account in terms of variation of viscosity, density and coefficient of diffusion. In particular, this coefficient is calculated from experimental data and expressed as a function of the wet bulb air temperature. When external conditions are modified and, as a natural consequence, also… More >

R. Abdeljabar¹, F. Onofri², M.J. Safi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.4, pp. 245-254, 2008, DOI:10.3970/fdmp.2008.004.245

Abstract This paper focuses on the mechanisms of convective instability in a stable salty gradient layer (i.e. an interfacial salty layer). This layer is assumed to be initially confined between two homogeneous liquid layers: a lower layer composed of salty water of 5wt% concentration and an upper layer composed of distilled water. The mechanisms underlying the interfacial salty layer's instability are depicted experimentally using a PIV technique and via measurements of concentration and temperature. It is found that in addition to the effect of double-diffusion across the interfacial salty layer, different forms of Kelvin-Helmholtz instability occur at different locations:\newline i. At… More >

T. J Jaber¹, M. Khawaja¹, M.Z. Saghir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.4, pp. 271-286, 2006, DOI:10.3970/fdmp.2006.002.271

Abstract This paper numerically investigates the interaction between thermodiffuion and buoyancy driven convection in a laterally heated vertical porous cavity for different permeability. The Firoozabadi model is applied to binary hydrocarbon mixtures: (i) the mixture of 1,2,3,4 tetrahydronaphtalene (THN) and dodecane (C12) with mass fraction of 50% for each component, (ii) 1,2,3,4 tetrahydronaphtalene and isobutylbenzene (IBB) with mass fraction of 50% for each component, and (iii) isobutylbenzene and dodecane with mass fraction of 50% for each component. The thermal and molecular diffusion coefficients, which are functions of the temperature and other properties of mixture, are calculated at each point of the… More >

M. Sekhon¹, N. Armour¹, S. Dost^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.4, pp. 331-351, 2013, DOI:10.3970/fdmp.2013.009.331

Abstract Liquid Phase Diffusion (LPD) growth of Si_xGe_1-x single crystals has been numerically simulated under zero gravity. The objective was to examine growth rate and silicon concentration distribution in the LPD grown crystals under diffusion dominated mass transport prior to the planned LPD space experiments on the International Space Station (ISS). Since we are interested in predicting growth rate and crystal composition, the gravitational fluctuation of the ISS (g-jitter) was neglected and the gravity level was taken as zero for simplicity.
A fixed grid approach has been utilized for the simulation. An integrated top-level solver was developed in OpenFOAM to carry… More >

S. Aggoune¹, E.H. Amara¹, M. Debiane²

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.1, pp. 61-75, 2013, DOI:10.3970/fdmp.2013.009.061

Abstract The effects of inert assisting gas nature and velocity on laser cut quality are investigated. A pure fusion cutting process just above melting point is considered, where the molten steel velocity is given as a function of the two acting forces represented by the pressure gradient and the frictional forces applied by the laminar gas flow. In the case of nitrogen assisting gas, the stainless steel melt film exhibits a visible separation point. The point where the melt flow is separated out from the solid wall depends strongly on the gas velocity. It is pushed down the cut surface when… More >